Process and apparatus for casting compound metal units.



Patented. Feb. 5, 1918.

m mm m Am W6 m MBA/A F. BURCHARTZ.

PROCESS AND APPARATUS FOR CASTING GOMPOUND METAL umns.

-' v APPLICATION FILED JAYLZB! 1,55,?Qfl.

UNllTiED %TATE% PATENT @ltl h lfifil FERDINAND BURGHAR'IZ, OF NEW YORK, N. Y. Y

PROCESS AND APPARATUS FOR CASTING COMPOUND METAL UNITS.

memos.

To all whom it may concern:

Be it known that I, FERDINAND BURCHARTZ,

a citizen of the United States, and resident ticular purpose of my improvement is to provide a simple and efliclent process whereby'said metals are intlmately connected together during castlng, ma comparatlvely inexpensive manner and with a maximum degree of uniformity at all times. A further object of my invention is to provide a process in which the admixture of the metals or alloys is restricted within predetermined limits in the region of contact and complete commingling of said metals or alloys is prevented. My improvement further contemplates the provision of a process whereby the compound units are cast in such a manner as to avoid the necessity for forging and so as to permit said units to be rolled or otherwise manipulated into final form without any preliminary reforming or I the like after the casting has been eflected. My invention further has in mlnd the provision of a simple and efficient apparatus whereby my improved process maybe effectively carried out and whereby uniform and maximumly efficient results will at all timesbe assured. Other objects of my improvement will appear from thedescripti on hereinafter and the features of novelty will be pointed out in the appended claims.

Reference is to be had to the accompanying drawings which by way of'example diagrammatically illustrate several forms of my improved apparatus andin which Figure 1 is a sectional viewlof one form thereof and Fig. 2 1s a similar viewof another form.

In carrying out my improved process I first introduce the desired quantity of one of the metals or alloys which is to form part of the unit into a suitable mold or the like, in a molten condition, the metalor alloy having the greatest specific gravity preferably being the onefirst introduced into Specification of Letters Patent.

which Patented Feb. 5, 1918.

Application filed January 28, 1916. Serial N o. 74,946.

the mold. While thisfirst metal or alloy is still in a molten condition, I introduce into the mold the desired quantity of the next metal or alloy which is to be included in the unit, the second metal or alloy being also in a molten condition and preferably of less specific gravity than the first metal or alloy.

7 Th introduction'or pouring of this second metal or alloy intothe mold upon the first metal or alloy therein is controlled or carried out in such a manner that the two metals or alloys will commingle orbecome mixed with each other only to a predetermined extent, provision being made toprevent agitation of the first metal or alloy at any point beyond the zone in which admixture with the second metal or alloy'is to take place.

If the unit is to consist of more than two metals or alloys, additional molten metals or alloys are similarly introduced successively and while the metals or alloys previously introduced are still substantially in a molten condition, care being taken each time to prevent an admixture of the two adjacent metals or alloys beyond the zone at commingling thereof is desired. After all of the metals or alloys have been introduced into the-mold as described the unit formed thereby is permitted to cool and solidify, this cooling and solidifying being substantially uniform throughout owing to the fact that all of the metals'or alloys. are combined in a molten condition and at substantially the same temperature thus preventing the formation of flaws, air or gas bubbles and the like in the unit. At the same timeby introducing-the several metals final metal or alloy from which it may be easily removed if necessary.

The above process maybe carried out in any suitable manner adapted to produce the desired results as for instance by means of either form of my improved apparatus shown in the drawings. As shown in Fig. 1 this apparatus comprises an upright mold 1 of any desired form and dimensions supported upon a suitable base 2 and into the upper end of which a tube 21 extends. Near its lower end the said tube 21 is provided with an internal apertured member 22 extending across the axis of said tube and se cured therein in any suitable manner; This 'form of my improved apparatus further includes a guard plate 23 located at a distance from and in axial alinement with the open end of the tube 21, said plate 23 being secured to the latter in any convenient manner as for instance by being suspended from the apertured member 22 in the manner indicated in Fig. 1. In this form of my improved apparatus the tube 21 with the guard plate 23 and apertured member 22 is vertically adjustable relatively to the mold or the latter is capable of moving downwardly relatively to the tube 21 and its connected parts for the purpose to be more fully set forth hereinafter, the relative adjustment of the tube or of the mold as the case may be, being accomplished through the medium of any suitable mechanism.

' In utilizing this form of my apparatus the first metal or alloy 1 in a molten condition is introduced into the mold 1 after which the tube 21 or the mold 1 is adjusted preferably so as to bring the guard plate r and possibly the lower end of said tube 21 beneath the upper surface of said metal or alloy 1 as shown for instance in Fig. 1, or so as to bring said guard plate into other cooperative relation with said upper surface of said metal or alloy 1. Or if desired the tube 21 and mold 1 may first be brought into cooperative relation with each other and the metal or alloy 1 then poured into the mold, either directly or through the tube 21. In either case the guard plate 23 is 1 preferably though not necessarily so adjusted as to occupy a position at a predetermined depth beneath the upper surface of which is to become admixed with the next succeeding metal or alloy. In other words the position of the guard plate 23 determines the extent and depth to which commingling of the metals or alloys is to be permitted and thus comprises a means whereby this result may be predetermined vand adjusted to secure the most satisfactory bond in any and all cases. After the above steps have taken place and while the metal or alloy 1" is still in a molten condition the second metal or alloy also in a molten condition, is poured into the tube 21 or otherwise introduced into the same. This second metal or alloy now flows downwardly through said tube 21 and impacts against the member 22 which thus arrests the speed of said molten metal and permitsit to flow at reduced speed through its apertures. After passing through the aperture member 22 the second metal or. alloy at a'minimum speed reaches the upper surface of the first metal or alloy 1, and becomes mixed with'the, portion of said metal or alloy'l which lies above the guard plate 23. Thisportion of metal or alloy 1 lying above the uard plate 23 in combination with the guard plate itself serves to still further arrest the flow of the second metal or alloy and prevents the same from in any way agitating or materially disturbing any part of that portion of the first metal or alloy 1 which is below said guard plate 23. After the desired amount of the second metal or'alloy has been introduced as described, the tube 21 with the guard plate'23 is evenly raised or the mold 1 is similarly lowered at a predetermined speed, the operation in either case causing the metals or alloys above the guard plate 23 to flow over the peripheral edge of the latter until the mold and tube 21with guard plate 23 have been completely separated. Owing to the restricted space between the peripheral edge of the plate 23 and the inner sur face of the mold the combination of the metals or alloys initially above and below the guard plate 23 respectively is accom- 'plished"without any material agitation of that portion of the metal or alloy 1 located below said guard plate. In this manner the commingling or admixture of the two metals or alloys is restricted to a predetermined zone determined by the original location of the guard plate 23 withrespect to the upper surface of the metal or alloy 1 The extent to which'suc-h admixture takes place or in other words the dimensions of'the commingling zone may also be adjusted by changing the dimensions of the apertures in the member 22 and the distance between the end of the tube 21 andthe guard plate 23 as well as by changing the size of the latter to increase or diminish the distance between the periphery of said plate and the inner surface of the mold. In addition to this different extents of admixture may be obtained by varying the speed at which the guard plate 23 is removed from the molten metals. In other words the different results in the dimensions or extent of the commin gling Zone maybe attained. either by regulating the speed of the inflowing metal or the degree and depth of agitatlon produced by theremoval of theguard plate, it being obvious that an increase in the speed of the intlowing second metal or alloy, or in the removal of the guard platewill cause the lartterto mix deeper with the first metal than would otherwise be the case. It will of course be understood that even though the initial position of theguard plate 23 in the mold 1 with respect to the metal or alloy 1 is otherwise than as shown and described, said guard plate will always be so located as to break the speed; and control theflow of the incoming successive molten mass of metal or alloy and will thus always restrict the commingling of the last named metal or alloy with the metalor alloy 1" to a predetermined Zone.

In the form of apparatus illustrated'in Fig. 2 thetube 21 corresponding to the tube 21 is providedwith a sleeve 2 which extends downwardly below the end of said tube and is adapted to receive and hold the neck 26., The latter forms part of or is secured to a guard plate 23 corresponding to the guard plate 23 and further is provided with one or more exit openings 25 whereby communication between .the chamber 27 formed by the neck '26 beneath the tube 217 and the mold 1 is established. Otherwise this form may be the sameas the one first described. 'Theoperation is also the same excepting that the molten second metal or alloy passes from the tube 21* into direct contact with a portion or the first metal or alloy located abovethe guard plate 9.3 and becomes mixed therewith through the opening as will be readily apparent. lVith the arrangement shownin Fig. 2 the guard plateis easily removable tromthe tube 21 so as to be readily exchangeable. In this latter formthe surfaces of the guard plate 23 may incline from the center toward the periphery and the. latter may be rounded in order that the metals or alloyswill flow evenlyand uniformly therefrom "throughout as the guard plate is raised or the mold is lowered to remove said guardplatc from the metals or alloys. f desired the guard plate may be provided. with apertures preterably inclined inwardly through which the metals or alloys mayflow as the guard plate is removed in the above described manner. It will be seen that in either form of apparatus illustrated the guard plates 23 and 23 serve .as a means whereby the lower stratum of metal or. alloy is protected against a gitation during the introduction of the next succeeding stratum of metal or alloy whereby a complete admixture of such. metals or al loys excepting in .a zone of predetermined extent is prevented, It will be understood, it the unit is' to comprise more than two strata of metals or alloys, that the metals or alloys are. successively introduced into the mold as above described. In some in stances instead of having the commingling zone along substantially straight. transverse lines, it may be desiredto have the admix ture of two metals or alloys vary in extent at difi'erent portions of said zone. For instance it may be desired to have the lower portions of said zone describe a curve or to have the second metal or alloy mixed with the first metal or alloyto a greater depth at the center of the unit than at the outer portions thereof; This may easily be accomplished by simply curving or otherwise forming the lower surface of the guard plates so that the first metal or alloy will be displaced and the second metal will oommingle therewith in substantial accordance with the form oil said lower surface of the guard plates. Equivalent results may be obtained with increased oliiciency by decreasing the space between the periphery of the guard plate and the inner surface of the mold to a minimum and by providing the guard plate in the neighborhood. of its central portion with apertures or slots of relatively large dimensions. With this latter arrangement the flow of the second metal or alloyis restricted at the periphery of the guard plate and takes place mainly through said apertures or slots at the central portion thereof, so that said second metal or alloy presses more deeply into the first metal or alloy atthe center of the unit than at the outer portions thereof as will be readily apparent.

The use of the guard plate in any form suitable for the intended purpose or its equivalent has many technical advantages. For instance it permits the individual metals or alloys intended to comprisethe finished unit to be poured one upon the other withoutinterruption so that at the finish of the casting operation the combined metals or alloys all have substantially the same temperature and thus cool and solidify concurrently and uniformly whereby the formation of flaws or the like due to uneven internal stresses is fli'OlClQCl and at the same time any foreign substances, air or gases and the like are permitted to escape through the incoming molten metal. The zones in which the commingling of the metals or alloys takes place are thus free from impurities and the formation of air or gas bubbles andblow holes is etliciently prevented. At the same time after the guard plate andtube have been properly adjusted for a given operation and the speed and flow of the metal or alloy has been properly determined all of the units cast under the conditions of each case will be combined together in a uniformly eiiicient manner. The tubes. and guard plates protect the molten metal during casting against contact with the atmosphere and thus prevent oxidation. A still further advantage is that the succeeding metal or alloy becomes thoroughly mixed with that portion of the next preceding metal or alloy which is above the guard plate, this being particularly true if the guard plate is only then removed. The strength of the connection zone between two metals or alloys may be tICljllStBCl and predetermlned throughout a" maximum range by changing the depth at which the guard plate is submergedin one of the metals or alloys and the speed at which it is caused to leave the same. A decided advantage resides in the fact that with I the employment of guard plates-compound My improved process may be utilized to produce compound metal units whiclrmay be rolled out into rails for'railroads and other purposes or manipulated into elements intended to form parts of buildings,

bridges, cranes and the like or formed into ships plates, boiler plates, plates for fire boxes of locomotives, etc, armor plates, protection shields, car wheels and in fact may be workedinto any desired form to produce elements composed of two or more metals or alloys having different physical characteristics such as for instance steel of different degrees of hardness cast iron and cast steel and the like. Owing to the perfect and uniform bond between the fdifferent strata of metals and alloys, such elements may be constructed efficiently with a minimum cross-section or with a cross-section no greater than if a single expensive metal is utilized; The process thus reduces the cost of manufacture and operation to a minimum and at the same time produces a compound unit of maximum efficiency for many purposes With my improved process the necessity for waiting until one stratum of metal or alloy has cooled to a prede termined degree before the next stratum is introduced, is also avoided thus obviating the necessity for careful and continuous attention on the part of the operator as is necessary when the subsequent metal or alloy must be added only at the instant the preceding metal or alloy hasrea'ched apredetermined condition of semi-solidity. The guard plate or its equivalent in whatever form used may be constructed of any suitable material and is preferably formed of a fireproof substance.

Idesireitt o be understoodthatthe termi nology as used in the claims is intended to include a combination of two metals, two alloys or a metal and an almy and that the said claims are to be construed accordingly.

Various changes in the specific forms shown and described may be madeivithin the scope of the claims withoutdeparting from the spirit of my invention,

Iclann: e V 1. The process of casting compound metallic units which consists'in first confining one mass of molten metal, pouring a second mass of molten metah'into contact'with said first molten and controlling the flow of the second mass whereby the admixture of said metals is limited toarestricted-Zone 2. Th rprocess of casting compound 'me- 7 tallie units which consists in first confining ,one mass of'molten metal, pouring a sec-7' 0nd mass of molten metal down upon said first molten mass and controlling :thefiow of the second mass whereby the extent to which said second mass passes into and mixes with the first mass is limited.

3. The process of casting compound the tallic units which consists in confining a mass of molten metal, dividing said mass into two strata without completelysep'arat ing same,, pouring a second mass of; molten metal into contact with "said firstfmolten mass and causing a mixture of saidintals only in that strata" oflthe first mass, with which the second mass/of metal contacts,

The'process of casting compound inetallic units which consists in confining "a massof molten metal, dividing said mass into two strata without completelyseparatmg same, pouring a second mass of molten metal upon said firstmolten massand regu latmg the flow of said second massso thata mixture of the two metals will take place only in the exposed-strata of the first mass. 5. An apparatus for casting compound metalllc units'comprising a mold adapted to and means for controlling the flow of succes sive masses of metalwhereby' the commin' gling of each succeeding massof metal {with l t ed within predetermined V limits,

6. An apparatus for casting compound d" metallic units comprlsing as mold adapted-1 to receivesuccessive masses of molten metal: and a plate located 1n said mold adapted to control the flow of anuncoming mass of metal whereby the commingling thereof with V the next preceding massof metal is-restricted to a predetermined Zone; 7

7. An apparatus for' castingf compound metallic units comprising a mold adapted to receive successive masses of molten metal,

and a plate adapted to be submerged inone 1 mass of metal at apredetermined depth and V V adapted to restrict the commingling of a 110 i receive successive masses of molten metal,"

the next preceding mass of metal is restrict: '1 1 5 succeeding mass of metal With said one mass to a predetermined zone.

8. An apparatus for casting compound metallic units comprising a mold adapted to receive successive masses of molten metal, and a plate adapted to be submerged in one mass of metal at a predetermined depth and adapted to restrict the commingling of a succeeding mass of metal with said one mass to a predetermined zone, said plate being adjustable and movable out of said combined masses.

9. An apparatus for casting compound metallic units comprising a mold adapted to receive successive masses of molten metal, and a plate adapted to be submerged in one mass of metal at a predetermined depth and adapted to restrict the commingling of a succeeding mass of metal With said one mass to a predetermined zone, one of said elements being adjustable to remove said plate from the molten metals.

10. An apparatus for casting compound metallic units comprising a mold adapted to receive an initial mass of molten metal, a tube through Which a second mass of metal is introduced into said mold subsequent to said first mass and a guard plate carried by said tube at a distance from the mouth thereof and adapted tobreak the speed of said second mass of metal and to restrict the commingling of said tWo metals to a predetermined zone.

11. An apparatus for casting compound metallic units comprising a mold adapted to receive an initial mass of molten metal, a tube through which a second mass of molten metal is introduced into said mold subsequent to said first mass, a guard plate carried by said tube at a distance from the mouth thereof and adapted to be submerged in said first mass of metal to divide the same into two strata and a perforated member in said tube whereby the speed of the second mass of metal out of said tube is controlled.

12. An apparatus for casting compound metallic units comprising a mold adapted to receive an initial mass of molten metal, a tube through which a second mass of mol' ten metal is introduced into said mold subsequent to said first mass, a sleeve carried by said tube and projecting beyond the exit end thereof, a tubular apertured neck removably held in said sleeve, and a guard plate carried by said neck and arranged to be submerged in said initial mass of metal whereby the commingling of said metals is restricted to a predetermined zone.

In testimony whereof I have hereunto set my hand.

FERDINAND BURCHARTZ.

Gopies of this patent may be obtained for five cents each, by addressing the "Gommlssioner oil Patents,

Washington, D. G. 

